Answer:
Step-by-step explanation:
For the first question, the first one is correct because:
a^2+b^2=c^2
where a and b are the two legs and C is the hypotheneuse of the triangle. 8 and y are the leg sides in this case.
So the equation is
8^2+y^2=12^2
For the second question:
we can change the equation to ;
y^2=12^2-8^2 ->
y^2=144-64 ->
y^2=80
